Relay node device for receiving control information from a base station and method therefor

ABSTRACT

The present invention relates to a relay node device for receiving control information from a base station and a method therefor. The relay node device according to the present invention comprises: a receiver, which receives information about an area where a relay-physical downlink control channel (R-PDCCH), the channel for transmitting control information for the relay node from a base station, is allocated; a processor, which searches for at least one R-PDCCH for the relay node based on the R-PDCCH allocation information received; and an R-PDCCH receiver, which receives the at least one R-PDCCH from the fourth symbol of the first slot in a downlink backhaul subframe of the area where the at least one R-PDCCH searched for by the processor has been allocated.

This application is a Continuation of, and claims the benefit of, U.S.patent application Ser. No. 14/324,785, filed on Jul. 7, 2014, which isa Continuation of U.S. patent application Ser. No. 13/503,616, filedApr. 23, 2012, which is a U.S.C. §371 National Stage entry ofInternational Application No. PCT/KR2010/007467, filed Oct. 28, 2010,and claims the benefit of U.S. Provisional Application No. 61/255,492,filed Oct. 28, 2009 and U.S. Provisional Application No. 61/324,313,filed Apr. 15, 2010, and Korean Application No. 10-2010-0105952, filedOct. 28, 2010, all of which are incorporated by reference in theirentirety herein.

TECHNICAL FIELD

The present invention relates to a wireless communication, and moreparticularly, to a relay node device for receiving control informationfrom a base station and method therefor.

BACKGROUND ART

In case that a channel status between an eNode B and a user equipment, arelay node (RN) is installed between the eNode B and the user equipment,thereby providing the user equipment with a radio channel having abetter channel status. Moreover, by introducing a relay node into a celledge area having a poor channel status from an eNode B, if the relaynode is used, it may provide a faster data channel and extend a cellservice area. Thus, a relay node is the technology introduced to solve aradio wave shadow area problem and is widely used.

Compared to a conventional relay node having a function limited to afunction of a repeater configured to simply amplify and transmit asignal, a recent relay node is evolved into a further-intellectual form.Moreover, the relay node technology corresponds to the technologyessential to service coverage extension and data throughput improvementas well as cost reductions for base station expansion and backhaulnetwork maintenance in a next generation mobile communication system. Tokeep up with the ongoing development of the relay node technology, it isnecessary for a new wireless communication system to support a relaynode used by the related art wireless communication system.

In 3GPP LTE-A system, a relay node is defined to transmit a signal to aneNode B via an uplink backhaul subframe and is also defined to receive asignal from the eNode B via a downlink backhaul subframe. However, anyframe structure for transceiving control information between a relaynode and an eNode B has not been proposed in detail yet.

DISCLOSURE OF THE INVENTION Technical Tasks

One object of the present invention is to provide a method for a relaynode to receive control information from an eNode B.

Another object of the present invention is to provide a relay nodedevice for receiving control information from an eNode B.

Technical tasks obtainable from the present invention may be non-limitedby the above mentioned technical tasks. And, other unmentioned technicaltasks can be clearly understood from the following description by thosehaving ordinary skill in the technical field to which the presentinvention pertains.

Technical Solutions

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, a method ofreceiving control information, which is received by an eNode B from arelay node, according to the present invention may include the steps ofreceiving information on a region, to which R-PDCCH (relay-physicaldownlink control channel) for transmitting the control information forthe relay node is assigned, from the eNode B, searching for at least oneR-PDCCH for the relay node based on the received information, andreceiving the at least one R-PDCCH by starting from a fourth symbol of afirst slot in a downlink backhaul subframe of the region, to which thesearched at least one R-PDCCH is assigned.

In the at least one R-PDCCH receiving step, the relay node may receive aDL grant including R-PDSCH (relay-physical downlink shared channel)resource allocation information and transmission format informationthrough the fourth symbol to a seventh symbol of the first slot in thedownlink backhaul subframe.

In the at least one R-PDCCH receiving step, the relay node may receive aUL grant including R-PUSCH (relay-physical uplink shared channel)resource allocation information in a second slot interval of thedownlink backhaul subframe. Alternatively, in the at least one R-PDCCHreceiving step, the relay node may receive a UL grant including R-PUSCH(relay-physical uplink shared channel) resource allocation informationin a second slot interval of a downlink backhaul subframe assigned to aphysical resource block (PRB) having a frequency band different fromthat of the down backhaul subframe.

The R-PDCCH assigned region may be configured by a physical resourceblock (PRB) unit.

The information on the R-PDCCH assigned region may be received from theeNode B by a higher layer signaling. And, the R-PDCCH assigned regionmay be semi-statically configured by the eNode B.

To further achieve these and other advantages and in accordance with thepurpose of the present invention, a relay node apparatus for receivingcontrol information from a eNode B, according to the present inventionmay include a receiver configured to receive information on a region, towhich R-PDCCH (relay-physical downlink control channel) for transmittingthe control information for the relay node is assigned, from the eNodeB, a processor configured to search for at least one R-PDCCH for therelay node based on the received information, and the receiver isfurther configured to receive the at least one R-PDCCH from a fourthsymbol of a first slot in a downlink backhaul subframe of the region, towhich the searched at least one R-PDCCH is assigned.

The receiver is further configured to receive the at least one R-PDCCHfurther may receive a DL grant including R-PDSCH (relay-physicaldownlink shared channel) resource allocation information andtransmission format information through the fourth symbol to a seventhsymbol of the first slot in the downlink backhaul subframe.

The receiver is further configured to receive the at least one R-PDCCHfurther may receive a UL grant including R-PUSCH (relay-physical uplinkshared channel) resource allocation information in a second slotinterval of the downlink backhaul subframe. Alternatively, the receiverreceiving the at least one R-PDCCH may further receive a UL grantincluding R-PUSCH (relay-physical uplink shared channel) resourceallocation information in a second slot interval of a downlink backhaulsubframe assigned to a physical resource block (PRB) having a frequencyband different from that of the down backhaul subframe.

The R-PDCCH assigned region may be configured by a physical resourceblock (PRB) unit.

The information on the R-PDCCH assigned region may be received from theeNode B by a higher layer signaling. And, the R-PDCCH assigned regionmay be semi-statically configured by the eNode B.

Advantageous Effects

According to the present invention, a relay node device efficientlyreceives control information from an eNode B, thereby enhancingperformance of communication with the eNode B.

In particular, a relay node may be able to efficiently receive controlinformation using an assigned position of R-PDCCH transmitted bycontaining control information for the relay node, a start point, an endpoint, multiplexing type information and the like.

According to various embodiments of the present invention, an eNode Band a relay node become aware of a UL backhaul subframe structurethrough signaling and the like, thereby efficiently performingcommunication.

Effects obtainable from the present invention may be non-limited by theabove mentioned effect. And, other unmentioned effects can be clearlyunderstood from the following description by those having ordinary skillin the technical field to which the present invention pertains.

DESCRIPTION OF DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention. In the drawings:

FIG. 1 is a diagram for configurations of a relay backhaul link and arelay access link in a wireless communication system;

FIG. 2 is a block diagram for configurations of an eNode B 205 and arelay node 210 in a wireless communication system 200;

FIG. 3 is a diagram for one example of a structure of a radio frame usedin 3GPP LTE system as one example of a mobile communication system;

FIGS. 4(a) and (b) are diagrams illustrating structures of downlink anduplink subframes in 3GPP LTE system as one example of a mobilecommunication system;

FIG. 5 is a diagram of a DL time-frequency resource grid structure usedby the present invention;

FIG. 6 is a diagram for one example of a multiplexing scheme for aneNode B to transmit R-PDCCH in a specific backhaul subframe to a relaynode; and

FIG. 7 is a diagram for one example of a multiplexing scheme for aneNode B to transmit R-PDCCH in a specific backhaul subframe to a relaynode.

BEST MODE FOR INVENTION

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. In the following detailed description of the inventionincludes details to help the full understanding of the presentinvention. Yet, it is apparent to those skilled in the art that thepresent invention can be implemented without these details. Forinstance, although the following descriptions are made in detail on theassumption that a mobile communication system includes 3GPP LTE system,the following descriptions are applicable to other random mobilecommunication systems in a manner of excluding unique features of the3GPP LTE.

Occasionally, to prevent the present invention from getting vaguer,structures and/or devices known to the public are skipped or can berepresented as block diagrams centering on the core functions of thestructures and/or devices. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or like parts.

Besides, in the following description, assume that a terminal is acommon name of such a mobile or fixed user stage device as a userequipment (UE), a mobile station (MS), an advanced mobile station (AMS)and the like. And, assume that a base station (BS) is a common name ofsuch a random node of a network stage communicating with a terminal as aNode B (NB), an eNode B (eNB), an access point (AP) and the like.Moreover, a relay may be named one of a relay node (RN), a relay station(RS), a relay and the like.

In a mobile communication system, a user equipment/relay node is able toreceive information in downlink and is able to transmit information inuplink as well. Informations transmitted or received by the userequipment/relay node may include various kinds of data and controlinformations. In accordance with types and usages of the informationstransmitted or received by the user equipment/relay node, variousphysical channels may exist.

FIG. 1 is a diagram for configurations of a relay backhaul link and arelay access link in a wireless communication system.

In 3GPP LTE-A (3^(rd) Generation Partnership Project Long TermEvolution-Advanced) system, as a relay node is introduced to play a roleof forwarding a link between an eNode B and a user equipment, links oftwo types differing from each other in attribute are applied to a ULcarrier frequency band and a DL carrier frequency band, respectively. Aconnection link part established between an eNode B and a relay node isrepresented in a manner of being defined as a backhaul link. Iftransmission is performed by FDD (frequency division duplex)) or TDD(time division duplex) using a DL resource, it may be represented as abackhaul downlink. If transmission is performed by FDD or TDD using a ULresource, it may be represented as a backhaul uplink.

On the other hand, a connection link part established between a relaynode and user equipments is represented in a manner of being defined asa relay access link. If transmission is performed via a relay accesslink using a DL frequency band (in case of FDD) or a resource of a DLsubframe (in case of TDD), it may be represented as an access downlink.If transmission is performed via a relay access link using a ULfrequency band (in case of FDD) or a resource of a UL subframe (in caseof TDD), it may be represented as an access uplink.

A relay node (RN) may receive information from an eNode B in relaybackhaul downlink or transmit information to the eNode B in relaybackhaul uplink. The relay node may transmit information to a userequipment in relay access downlink or receive information from the userequipment in relay access uplink.

A relay node may be able to perform such an initial cell search as a jobof matching synchronization with an eNode B and the like. To this end,the relay node may receive a synchronization channel from the eNode B,match synchronization with the eNode B, and then acquire suchinformation as cell ID and the like. Subsequently, the relay node may beable to acquire intra-cell broadcast information by receiving a physicalbroadcast channel from the eNode B. Meanwhile, in the step of theinitial cell search, the relay node may check a channel status of arelay backhaul downlink by receiving a relay backhaul downlink referencesignal. In addition, the relay node may be able to detailed systeminformation by receiving R-PDCCH (Relay-Physical Downlink ControlCHannel) and/or R-PDSCH (Relay-Physical Downlink Shared CHannel).

Meanwhile, if an eNode B is initially accessed or a radio resource forsignal transmission is absent, a relay node may perform a random accessprocedure. To this end, the relay node may transmit a preamble via aphysical random access channel (PRACH) or the like and then receive aresponse message in response to the random access via R-PDCCH or acorresponding R-PDSCH.

In case of a contention based random access except a case of handover,it may be able to perform such a contention resolution procedure as atransmission of an additional physical random access channel, anR-PDCCH/R-PDSCH reception.

After completion of the above-described procedures, the relay node mayperform such a general UL/DL signal transmission procedure asR-PDCCH/R-PDSCH and R-PUSCH/R-PUCCH (Relay-Physical Uplink SharedCHannel/Relay-Physical Uplink Control CHannel) transmission.

In doing so, control information, which is transmitted to the eNode B inuplink by the relay node or received from the relay node by the eNode B,may include one of ACK/NACK signal, CQI (Channel Quality Indicator), PMI(Precoding Matrix Index), RI (Rank Indicator) and the like. In case of3GPP LTE (3^(rd) Generation Partnership Project Long Term Evolution)LTE-A system, a relay node may be able to transmit such controlinformation as CQI, PMI, RI and the like on R-PUSCH/R-PUCCH.

FIG. 2 is a block diagram for configurations of an eNode B 205 and arelay node 210 in a wireless communication system 200.

Although one eNode B 205 and one relay node 210 are shown in the drawingto schematically represent a wireless communication system 200, thewireless communication system 200 may include at least one eNode Band/or at least one relay node.

Referring to FIG. 2, an eNode B 205 may include a transmitted (Tx) dataprocessor 215, a symbol modulator 220, a transmitter 225, a transceivingantenna 230, a processor 280, a memory 285, a receiver 290, a symboldemodulator 295 and a received data processor 297. And, a relay node 210may include a transmitted (Tx) data processor 265, a symbol modulator270, a transmitter 275, a transceiving antenna 235, a processor 255, amemory 260, a receiver 240, a symbol demodulator 245 and a received dataprocessor 250. Although the eNode B/relay node 205/210 includes oneantenna 230/235 in the drawing, each of the eNode B 205 and the relaynode 210 includes a plurality of antennas. Therefore, each of the eNodeB 205 and the relay node 210 of the present invention supports an MIMO(multiple input multiple output) system. In addition, the eNode B 205according to the present invention may support both SU-MIMO (singleuser-MIMO) and MU-MIMO (multi user-MIMO) systems.

In downlink, the transmitted data processor 215 receives traffic data,codes the received traffic data by formatting the received traffic data,interleaves the coded traffic data, modulates (or symbol maps) theinterleaved data, and then provides modulated symbols (data symbols).The symbol modulator 220 provides a stream of symbols by receiving andprocessing the data symbols and pilot symbols.

The symbol modulator 220 multiplexes the data and pilot symbols togetherand then transmits the multiplexed symbols to the transmitter 225. Indoing so, each of the transmitted symbols may include the data symbol,the pilot symbol or a signal value of zero. In each symbol duration,pilot symbols may be contiguously transmitted. In doing so, the pilotsymbols may include symbols of frequency division multiplexing (FDM),orthogonal frequency division multiplexing (OFDM), or code divisionmultiplexing (CDM).

The transmitter 225 receives the stream of the symbols, converts thereceived stream to at least one or more analog signals, additionallyadjusts the analog signals (e.g., amplification, filtering, frequencyupconverting), and then generates a downlink signal suitable for atransmission on a radio channel. Subsequently, the downlink signal istransmitted to the relay node via the antenna 230.

In the configuration of the relay node 210, the antenna 235 receives thedownlink signal from the eNode B and then provides the received signalto the receiver 240. The receiver 240 adjusts the received signal (e.g.,filtering, amplification and frequency downconverting), digitizes theadjusted signal, and then obtains samples. The symbol demodulator 245demodulates the received pilot symbols and then provides them to theprocessor 255 for channel estimation.

The symbol demodulator 245 receives a frequency response estimated valuefor downlink from the processor 255, performs data demodulation on thereceived data symbols, obtains data symbol estimated values (i.e.,estimated values of the transmitted data symbols), and then provides thedata symbols estimated values to the received (Rx) data processor 250.The received data processor 250 reconstructs the transmitted trafficdata by performing demodulation (i.e., symbol demapping, deinterleavingand decoding) on the data symbol estimated values.

The processing by the symbol demodulator 245 and the processing by thereceived data processor 250 are complementary to the processing by thesymbol modulator 220 and the processing by the transmitted dataprocessor 215 in the eNode B 205, respectively.

In the relay node 210 in uplink, the transmitted data processor 265processes the traffic data and then provides data symbols. The symbolmodulator 270 receives the data symbols, multiplexes the received datasymbols, performs modulation on the multiplexed symbols, and thenprovides a stream of the symbols to the transmitter 275. The transmitter275 receives the stream of the symbols, processes the received stream,and generates an uplink signal. This uplink signal is then transmittedto the eNode B 205 via the antenna 135.

In the eNode B 205, the uplink signal is received from the relay node210 via the antenna 230. The receiver 290 processes the received uplinksignal and then obtains samples. Subsequently, the symbol demodulator295 processes the samples and then provides pilot symbols received inuplink and a data symbol estimated value. The received data processor297 processes the data symbol estimated value and then reconstructs thetraffic data transmitted from the relay node 210.

The processor 255/280 of the relay node/eNode B 210/205 directsoperations (e.g., control, adjustment, management, etc.) of the relaynode/eNode B 210/205. The processor 255/280 may be connected to thememory unit 260/285 configured to store program codes and data. Thememory 260/285 is connected to the processor 255/280 to store operatingsystems, applications and general files.

The processor 255/280 may be called one of a controller, amicrocontroller, a microprocessor, a microcomputer and the like. And,the processor 255/280 may be implemented using hardware, firmware,software and/or any combinations thereof. In the implementation byhardware, the processor 255/280 may be provided with one of ASICs(application specific integrated circuits), DSPs (digital signalprocessors), DSPDs (digital signal processing devices), PLDs(programmable logic devices), FPGAs (field programmable gate arrays),and the like.

In case of implementing the embodiments of the present invention usingfirmware or software, the firmware or software may be configured toinclude modules, procedures, and/or functions for performing theabove-explained functions or operations of the present invention. And,the firmware or software configured to implement the present inventionis loaded in the processor 255/280 or saved in the memory 260/285 to bedriven by the processor 255/280.

Layers of a radio protocol between a relay node and an eNode B may beclassified into 1^(st) layer L1, 2^(nd) layer L2 and 3^(rd) layer L3based on 3 lower layers of OSI (open system interconnection) model wellknown to communication systems. A physical layer belongs to the 1^(st)layer and provides an information transfer service via a physicalchannel. RRC (radio resource control) layer belongs to the 3^(rd) layerand provides control radio resourced between UE and network. A relaynode and an eNode B may be able to exchange RRC messages with each othervia radio communication layer and RRC layers.

FIG. 3 is a diagram for one example of a structure of a radio frame usedin 3GPP LTE system as one example of a mobile communication system.

Referring to FIG. 3, one radio frame has a length of 10 ms(327,200·T_(s)) and is constructed with 10 subframes in equal size. Eachof the subframes has a length of 1 ms and is constructed with two slots.Each of the slots has a length of 0.5 ms (15,360·T_(s)). In this case,T_(s) indicates a sampling time and is expressed as T_(s)=1/(15kHz×2,048)=3.2552×10⁻⁸ (about 33 ns). The slot includes a plurality ofOFDM symbols or SC-FDMA symbols in a time domain and also includes aplurality of resource blocks (RBs) in a frequency domain.

In the LTE system, one resource block (RB) includes ‘12 subcarriers×7 or6 OFDM or SC-FDMA (single carrier-frequency division multiple access)symbols’. A transmission time interval (hereinafter abbreviated TTI),which is a unit time for transmitting data, can be determined by atleast one subframe unit. The above-described structure of the radioframe is just exemplary. And, the number of subframes included in aradio frame, the number of slots included in a subframe and/or thenumber of OFDM or SC-FDMA symbols included in a slot may be modified invarious ways.

FIG. 4 is a diagram for structures of downlink and uplink subframe in3GPP LTE system as one example of a mobile communication system.

Referring to FIG. 4(a), one downlink (hereinafter abbreviated DL)subframe includes 2 slots in a time domain. Maximum 3 fore OFDM symbolsof the first slot within the DL subframe correspond to a control regionfor allocating control channels thereto and the rest of the OFDM symbolscorrespond to a data zone for allocating PDSCH (physical downlink sharedchannel) thereto.

DL (downlink) control channels used in 3GPP LTE system or the likeinclude PCFICH (physical control format indicator channel), PDCCH(physical downlink control channel), PHICH (physical hybrid-ARQindicator channel), etc. The PCFICH carried on a first OFDM symbolcarries the information on the number of OFDM symbols (i.e., a size of acontrol region) used for the transmission of control channels within asubframe. The control information carried on the PDCCH is calleddownlink control information (hereinafter abbreviated DCI). The DCIindicates a UL resource allocation information, a DL resource allocationinformation, a UL transmission power control command for random userequipment groups and the like. The PHICH carries ACK/NACK(acknowledgement/not-acknowledgement) signal for UL HARQ (hybridautomatic repeat request). In particular, the ACK/NACK signal for ULdata transmitted by a user equipment is carried on PHICH.

In the following description, PDCCH of DL physical channel is explained.

First of all, an eNode B is able to transmit resource allocation andtransmission format (this is so-called DL grant) of PDSCH, resourceallocation information (this is so-called UL grant) of a physical ULshared channel, an aggregation of transmission power control commandsfor a random user equipment and individual user equipments in a group,activation of VoIP (voice over internet protocol) and the like viaPDCCH. A plurality of PDCCHs may be transmitted within a control regionand a user equipment may be able to monitor a plurality of the PDCCHs.The PDCCH is constructed with aggregation of one or several contiguousCCEs (control channel elements). The PDCCH constructed with theaggregation of one or several CCEs may be transmitted via the controlregion after completion of subblock interleaving. The CCE is a logicalallocation unit used to provide the PDCCH with a coding rate inaccordance with a status of a radio channel. The CCE corresponds to aplurality of resource element groups. The format of the PDCCH and thebit number of available PDCCH are determined in accordance with thecorrelation between the number of CCEs and the coding rate provided bythe CCEs.

The control information carried on the PDCCH may be called DL controlinformation (hereinafter abbreviated DCI). Table 1 shows the DCIaccording to DCI format.

TABLE 1 DCI Format Description DCI format 0 used for the scheduling ofPUSCH DCI format 1 used for the scheduling of one PDSCH codeword DCIformat 1A used for the compact scheduling of one PDSCH codeword andrandom access procedure initiated by a PDCCH order DCI format 1B usedfor the compact scheduling of one PDSCH codeword with precodinginformation DCI format 1C used for very compact scheduling of one PDSCHcodeword DCI format 1D used for the compact scheduling of one PDSCHcodeword with precoding and power offset information DCI format 2 usedfor scheduling PDSCH to UEs configured in closed-loop spatialmultiplexing mode DCI format 2A used for scheduling PDSCH to UEsconfigured in open-loop spatial multiplexing mode DCI format 3 used forthe transmission of TPC commands for PUCCH and PUSCH with 2-bit poweradjustments DCI format 3A used for the transmission of TPC commands forPUCCH and PUSCH with single bit power adjustments

DCI format 0 indicates UL resource allocation information, DCI format1˜2 indicates DL resource allocation information, and DCI format 3 or 3A indicates a transmission power control (hereinafter abbreviated TPC)command for random UE groups.

A scheme for an eNode B to map a resource for PDCCH transmission in LTEsystem is schematically described as follows.

Generally, an eNode B may be able to transmit scheduling allocationinformation and other control informations via PDCCH. A physical controlchannel may be transmitted as one aggregation or a plurality ofcontiguous control channel elements (CCEs). In this case, one controlchannel element (hereinafter abbreviated CCE) includes 9 resourceelement groups (REGs). The number of REGs failing to be allocated toPCFICH (physical control format indicator channel) or PHICH (physicalhybrid automatic repeat request indicator channel) is N_(REG). Thenumber of CCEs available for a system ranges 0 to ‘N_(CCE)−1’, whereN_(CCE)└N_(REG)/9┘. The PDCCH supports such a multiple format as shownin Table 2. One PDCCH including n contiguous CCEs starts with a CCE thatexecutes ‘i mod n=0’, where ‘i’ is a CCE number. Multiple PDCCHs may betransmitted in one subframe.

TABLE 2 PDCCH Number of Number of resource- Number of format CCEselement groups PDCCH bits 0 1 9 72 1 2 18 144 2 4 36 288 3 8 72 576

Referring to Table 2, an eNode B is able to determine a PDCCH format inaccordance with how many regions will receive control information andthe like. And, a user equipment is able to reduce overhead by readingthe control information and the like by CCE unit. Likewise, a relay nodemay be able to read control information and the like by R-CCE unit. InLTE-A system, it may be able to map a resource element (RE) by R-CCE(relay-control channel element) unit in order to transmit R-PDCCH for arandom relay node.

Referring to FIG. 4(b), a UL subframe can be divided into a controlregion and a data region in a frequency domain. The control region isallocated to a physical UL control channel (PUCCH) carrying UL controlinformation. And, the data region is allocated to a physical UL sharedchannel (PUSCH) for carrying user data. In order to maintain the singlecharier property, one user equipment does not transmit PUCCH and PUSCHsimultaneously. PUCCH for one user equipment is allocated as an RB pairin one subframe. RBs belonging to the RB pair occupy differentsubcarriers in two slots, respectively. And, frequency hopping isperformed on the RB pair allocated to the PUCCH on a slot boundary.

FIG. 5 is a diagram of a downlink time-frequency resource grid structureused by the present invention.

A DL signal transmitted in each slot uses a resource grid structureconstructed with N_(RB) ^(DL)×N_(SC) ^(RB) subcarriers and N_(symb)^(DL) OFDM (Orthogonal Frequency Division Multiplexing) symbols. In thiscase, ‘N_(RB) ^(DL)’ indicates the number of resource blocks (RBs) inDL, ‘N_(SC) ^(RB)’ indicates the number of subcarriers constructing oneRB, and ‘N_(symb) ^(DL)’ indicates the number of OFDM symbols in one DLslot. A size of ‘N_(RB) ^(DL)’ varies in accordance with a DLtransmission bandwidth configured within a cell and should meet ‘N_(RB)^(min,DL)≦N_(RB) ^(DL)≦N_(RB) ^(max,DL)’. In this case, ‘N_(RB)^(min,DL)’ is a smallest DL bandwidth supported by a wirelesscommunication system and ‘N_(RB) ^(max,DL)’ a greatest DL bandwidthsupported by the wireless communication system. It may become ‘N_(RB)^(min,DL)=6’ and ‘N_(RB) ^(max,DL)=110’, by which the present example isnon-limited. The number of the OFDM symbols included in one slot canvary in accordance with a length of a CP (cyclic prefix) and an intervalof subcarrier. In caser of multi-antennal transmission, one resourcegrid can be defined for each antenna port.

Each element within the resource grid for each antenna port is called aresource element (hereinafter abbreviated RE) and is uniquely identifiedby an index pair (k, l) within a slot. In this case, ‘k’ is an index ina frequency domain and ‘l’ is an index in a time domain. The ‘k’ has avalue selected from ‘0, . . . , N_(RB) ^(DL)N_(SC) ^(RB)−1’ and the ‘l’has a value selected from ‘0, . . . , N_(symb) ^(DL)−1’.

The resource block shown in FIG. 5 is used to describe the mappingrelation between a prescribed physical channel and resource elements.Resource blocks can be classified into physical resource blocks (PRBs)and virtual resource blocks (VRBs). One PRB can be defined by N^(DL)_(symb) contiguous OFDM symbols in time domain and N^(RB) _(SC)contiguous subcarriers in frequency domain. In this case, ‘N_(symb)^(DL)’ and ‘N_(SC) ^(RB)’ can be given as shown in Table 3. Hence, onePRB is constructed with ‘N_(symb) ^(DL)×N_(SC) ^(RB)’ resource elements.One PRB corresponds to one slot in time domain and also corresponds to180 kHz in frequency domain, by which the present example isnon-limited.

[Table 3]

TABLE 3 Configuration N_(sc) ^(RB) N_(symb) ^(DL) Normal Δf = 15 kHz 127 cyclic prefix Extended Δf = 15 kHz 6 cyclic  Δf = 7.5 kHz 24 3 prefix

PRB has a value ranging 0 to ‘N_(RB) ^(DL)−1’ in frequency domain. Therelation between the PRB number (n_(PRB)) in frequency domain and theresource element (k, l) in one slot satisfies ‘n_(PRB)=└k/N_(sc)^(RB)┘’.

In this case, a size of the VRB is equal to that of PRB. The VRB can bedefined in a manner of being categorized into a localized VRB(hereinafter abbreviated LVRB) and a distributed VRB (hereinafterabbreviated DVRB). For the VRB of each type, a single VRB number n_(VRB)is allocated to a pair of VRBs in two slots within one subframe.

The VRB may have a size equal to that of the PRB. VRBs of two types maybe defined as follows. First of all, the first type is the localized VRB(LVRB). And, the second type is the distributed VRB (DVRB). For the VRBof each of the types, a pair of VRBs are allocated across two slots ofone subframe with a single VRB index (hereinafter named a VRB number).In particular, one index selected from the group consisting of 0 to‘N_(RB) ^(DL)−1’ is allocated to N_(RB) ^(DL) VRBs belonging to a firstone of the two slots constructing one subframe. And, one index selectedfrom the group consisting of 0 to ‘N_(RB) ^(DL)−1’ is allocated toN_(RB) ^(DL) VRBs belonging to a second one of the two slotsconstructing one subframe as well.

As mentioned in the foregoing description with reference to FIGS. 3 to5, the radio frame structure, the DL and UL subframes, the downlinktime-frequency resource grid structure and the like may be applicablebetween an eNode B and a relay node.

In the following description, a process for an eNode B to send PDCCH toa user equipment in downlink is explained. First of all, an eNode Bdetermines a PDCCH format in accordance with a DCI (downlink controlinformation) which is to be sent to a user equipment and then attaches aCRC (cyclic redundancy check) to a control information. In this case,the CRC is masked with a unique identifier, which will be called a radionetwork temporary identifier (hereinafter abbreviated RNTI), inaccordance with an owner or usage of PDCCH. If the PDCCH is provided fora specific user equipment, the CRC can be masked with a uniqueidentifier of a user equipment, e.g., C-RNTI (cell-RNTI). If the PDCCHis provided to a paging message, the CRC can be masked with a pagingindication identifier, e.g., P-RNTI (paging-RNTI). If the PDCCH isprovided for a system information, the CRC can be masked with a systeminformation identifier, e.g., SI-RNTI (system information-RNTI). Inorder to indicate a random access response which is the response to atransmission of a random access preamble of a user equipment, the CRCcan be masked with RA-RNTI (random access-RNTI). Table 4 shows examplesof an identifier that masks PDCCH.

TABLE 4 Type Identifier Description UE- C-RNTI used for the UEcorresponding to the specific C-RNTI. Common P-RNTI used for pagingmessage. SI-RNTI used for system information (It could be differentiatedaccording to the type of system information). RA-RNTI used for randomaccess response (It could be differentiated according to subframe orPRACH slot index for UE PRACH transmission). TPC-RNTI used for uplinktransmit power control command (It could be differentiated according tothe index of UE TPC group).

If C-RNTI is used, PDCCH carries a control information for acorresponding specific user equipment. If a different RNTI is used,PDCCH carries a shared control information received by all or aplurality of user equipments within a cell. The eNode B generates acoded data by performing a channel coding on the CRC attached DCI. Thebase station then performs a rate matching according to the number ofCCEs allocated to the PDCCH format. subsequently, the eNode B generatesmodulated symbols by modulating the coded data. Thereafter, the eNode Bmaps the modulated symbols to the physical resource elements.

R-PDCCH (relay-physical downlink control channel) used by the presentinvention may be used to mean a backhaul physical downlink controlchannel for a relay transmission from an eNode B to a relay node. And,R-PUCCH (relay-physical uplink control channel) used by the presentinvention may be used to mean a backhaul physical uplink control channelfor a relay transmission to an eNode B from a relay node. R-PDSCH(relay-physical downlink shared channel) may be used to mean a backhauldownlink physical data/shared channel for a relay transmission. And,R-PUSCH (relay-physical uplink shared channel) may be used to mean abackhaul uplink physical data/shared channel for a relay transmission.

Moreover, a relay node used by the present invention is assumed asHalf-Duplex relay node incapable of simultaneously interactivetransmission/reception on the same band. Yet, the relay node used by thepresent invention may be non-limited by the Half-Duplex relay node.

In the following description, explained is a method for allocating aresource for R-PDCCH which is a new DL control channel to support arelay node in LTE-A system. In particular, in viewpoint of multiplexingbetween R-PDSCH (relay-physical downlink shared channel) (i.e., adownlink data channel for a relay node) and PRSCH (physical downlinkshared channel) for macro UEs belonging to a donor cell proposed are aTDM/FDM (time division multiplexing/frequency division multiplexing)multiplexing scheme, an FDM-only multiplexing scheme and a hybridmultiplexing scheme of the two schemes.

First of all, how a user equipment in LTE system receives PDCCH isdescribed as follows. A plurality of PDCCHs can be transmitted in onesubframe and a user equipment monitors a plurality of the PDCCHs in eachsubframe. In this case, the ‘monitoring’ means that the user equipmentattempts to decode each of the PDCCHs in accordance with a monitoredPDCCH format. In the control region allocated within the subframe, aneNode B does not provide the user equipment with information indicatingwhere the corresponding PDCCH is located. The user equipment searchesthe PDCCH of its own by monitoring a set of PDCCH candidates in thesubframe. This is called blind decoding. For instance, if CRC error isnot detected from demasking the corresponding PDCCH from its C-RNTI, theuser equipment may detect the PDCCH as having a DCI of the userequipment.

In order to receive DL data, a user equipment preferentially receivesdownlink (DL) resource allocation on PDCCH. If detection of PDCCH issuccessfully completed, the user equipment reads a DCI on the PDCCH.Using the DL resource allocation in the DCI, the user equipment mayreceive DL data on PDSCH. In order to transmit UL data, the userequipment preferentially receives UL resource allocation on PDCCH. Ifdetection of PDCCH is successfully completed, the user equipment reads aDCI on the PDCCH. Using the UL resource allocation in the DCI, the userequipment may transmit UL data on PUSCH.

In the following description, a process for a relay node to receivecontrol information from an eNode B is explained. First of all, anR-PDCCH search space may mean a space for a relay node to search toreceive control information sent down on R-PDCCH from an eNode B. Adonor base station (hereinafter called an eNode B) may be able to set upan R-PDCCH search space for each relay node. An eNode B may be able toset up an R-PDCCH search space donor-cell-specifically in form of acommon search space for all relay nodes within a donor cell. In thiscase, every relay node within the donor cell may perform a blind searchto receive control information in the common search space.

An eNode B may be able to transmit such R-PDCCH as a DL grant, a ULgrant, a TPC (transmit power control) command and the like to each relaynode via a common search space in a manner of CRC (cyclic redundancycheck) masking the R-PDCCH with a relay node ID (identifier). The eNodeB transmits R-PDSCH assignment information for cell-specific systeminformation transmission in a manner of CRC masking the R-PDSCHassignment information with a relay node common ID (similar to SI-RNTIof LTE system).

On the other hand, an eNode B may be able to set up an RN-specificsearch space.

An eNode B may be able to set up a search space for R-PDCCH in frequencydomain by unit of PRB (physical resource block), configuredsemi-statically by a higher layer signaling. PRBs, on which R-PDCCHtransmission is not actually performed, among PRBs (hereinafter named arelay zone) semi-statically configured for the R-PRCCH transmission maybe used for PRSCH transmission for a macro UE or R-PRSCH transmissionfor a relay node.

In the following description, a case for an eNode B to transmit R-PDCCHfor a specific relay node is explained as follows. First of all, aneNode B may be able to transmit at least one R-PDCCH for a specificrelay node. In doing so, the eNode B may be able to transmit the atleast one R-PDCCH for the specific relay node in a manner ofmultiplexing the at least one R-PDCCH by TDM using the same RB or OFDMsymbols contiguous in the same RB pair. For instance, an eNode Btransmits a 1^(st) R-PDCCH in a given RB pair through 4 OFDM symbolscorresponding to OFDM symbol indexes 3 to 6 of a 1^(st) slot and alsotransmits a 2^(nd) R-PDCCH in a 2^(nd) slot of the corresponding RBpair. In this case, a plurality of R-PDCCHs may include R-PDCCHs usingdifferent formats.

For instance, formats of a plurality of R-PDCCHs may include R-PDCCHformat 1 for transmitting a DL grant which is control informationnecessary for an eNode B to transmit data to a relay node, R-PDCCHformat 2 for transmitting a DL grant which is control informationnecessary for an eNode B to transmit data to a relay node, and R-PDCCHformat 0 for transmitting a UL grant which is control informationnecessary for a relay node to transmit data to an eNode B. In this case,the DL grant may be transmitted in a manner of being assigned to a1^(st) slot and the UL grant may be transmitted in a manner of beingassigned to a 2^(nd) slot contiguous with the 1^(st) slot. Inparticular, the eNode B transmits the DL grant via 4 contiguous OFDMsymbols having OFDM symbol indexes 3 to 6 in the 1^(st) slot and alsotransmits the UL grant via 7 contiguous OFDM symbols having OFDM symbolindexes 7 to 13 in the 2^(nd) slot.

When an eNode B transmits at least one R-PDCCH to a specific relay node,the corresponding relay node may know an RB position, on which oneR-PDCCH is carried toward the corresponding relay node, through a blindsearch for another R-PDCCH. In particular, the R-PDCCH toward thecorresponding relay node may be multiplexed by TDM scheme through anOFDM symbol adjacent to the same frequency position.

In case that a relay node detects one R-PDCCH, the relay node may be setto perform blind decoding on contiguous OFDM symbols one more time. Ifthe relay node succeeds in additional R-PDCCH reception of a differentformat through the blind decoding of the contiguous OFDM symbols, therelay node may be able to another blind decoding on next contiguous OFDMsymbols. Subsequently, the relay node may be able to continue performingthe blind decoding until failing in additional R-PDCCH detection fromthe corresponding RB pairs.

In the following description, a method for an eNode B to transmitR-PDCCH for a relay node is explained with reference to the accompanyingdrawing.

FIG. 6 is a diagram for one example of a multiplexing scheme for aneNode B to transmit R-PDCCH in a specific backhaul subframe to a relaynode.

Referring to FIG. 6, an eNode B transmits R-PDCCH on both edge bands ofa DL frequency band in a manner of multiplexing the R-PDCCH by FDM. And,the eNode B may be able to transmit R-PDCCH in a semi-staticallyconfigured relay zone by multiplexing the R-PDCCH by TDM/FDM. A startpoint OFDM symbol for an R-PDCCH transmission of an eNode B may be fixedto a 4^(th) symbol (i.e., symbol of an index 3) in each of an FDM region610 and a TDM/FDM region 620.

A start point OFDM symbol of R-PDCH may be set in accordance with an RBsize of a DL frequency band. For instance, if a DL frequency band isequal to or greater than 10 RBs (resource blocks), a start point ofR-PDCCH may be set to a 4^(th) OFDM symbol of a 1^(st) slot. For anotherinstance, if a DL frequency band is smaller than 10 RBs (resourceblocks), a start point of R-PDCCH may be set to a 5^(th) OFDM symbol.Alternatively, in accordance with a PDCCH size of MBSFN (multimediabroadcast multicast service single frequency network) subframe set up bya relay node or a PDCCH size of an eNode B, an R-PDCCH start point OFDMsymbol may be semi-statically configured through a higher layersignaling. In this case, the R-PDCCH start point OFDM symbol may be setto a 3^(rd) OFDM symbol.

On the other hand, a start point of an R-PDCCH transmission may be fixedto a 4^(th) OFDM symbol of a 1^(st) slot in which a reception of a relaynode is secured irrespective of a DL frequency band (bandwidth).Moreover, a time domain size of R-PDCH of the TDM/FDM region 620 or anOFDM symbol for an R-PDCCH transmission may be fixed cell-specificallyor RN-specifically or may be configured semi-statically through a higherlayer signaling.

According to one embodiment of the above description, a final symbol ofa 1^(st) slot is determined as a final OFDM symbol for an R-PDCCHtransmission or the number of symbols used for the R-PDCCH transmissionmay be set to 2 OFDM symbols (i.e., 4^(th) and 5^(th) OFDM symbols ofthe 1^(st) slot) of the 1^(st) slot, by R-REG (Relay-Resource ElementGroup) and R-CCE (Relay-Control Channel Elements) setup schemes.Although one example of the R-PDCCH size and end point has beendescribed, a different size of the R-PDCCH may be set or the end pointof the R-PDCCH may be set to another position.

Referring to FIG. 6, an end point of the R-PDCCH of the FDM region 610established at the frequency band edge may be set as a final symbol of acorresponding backhaul subframe. If a final symbol is set as a guardperiod for RF switching (i.e., a switching for a relay node to switch areceiving mode to a transmitting mode), the end point may be set to asymbol right previous to the final symbol. One R-PDCCH in the FDM region610 shown in FIG. 6, may be transmitted in a manner of slot boundaryhopping.

FIG. 7 is a diagram for one example of a multiplexing scheme for aneNode B to transmit R-PDCCH in a specific backhaul subframe to a relaynode.

Referring to FIG. 7, like FIG. 6, an eNode B transmits R-PDCCH on bothedge bands of a DL frequency band in a manner of multiplexing theR-PDCCH by FDM. And, the eNode B may be able to transmit R-PDCCH in asemi-statically configured relay zone by multiplexing the R-PDCCH byTDM/FDM. A start point OFDM symbol for an R-PDCCH transmission of aneNode B may be fixed to a 4^(th) symbol (i.e., symbol of an index 3) ineach of an FDM region 710 and a TDM/FDM region 720.

In the FDM region 710, the eNode B may be able to transmit R-PDCCHs to arelay node by interleaving the R-PDCCHs through the same symbols in twoPRBs paired together. When R-CCE is mapped to RE (resource element),mapping may be preferentially performed on a time axis or a frequencyaxis except REs used as a reference signal.

Unlike FIG. 6 or FIG. 7, an eNode B may be able to transmit R-PDCCH in amanner of multiplexing the R-PDCCH by FDM on both edge bands of asemi-statically configured relay zone instead of both edge bands of a DLfrequency band and may be able to transmit R-PDCCH in a manner ofmultiplexing the R-PDCCH by TDM/FDM in an inner region of the relayzone. In this case, the transmission structure in the FDM region and thetransmission structure in the TDM/FDM region are identical to thoseshown in FIG. 6 and FIG. 7.

An eNode B separately sets up a relay zone setup information containingan information on RBs semi-statically configured for the TDM/FDM regionfor carrying the TDM/FDM multiplexed R-PDCCH and a relay zone setupinformation containing an information on RBs semi-statically configuredfor the FDM region for carrying the FDM multiplexed R-PDCCH and may bethen able to inform a relay node of the relay zone setup informations.

An eNode B transmits R-PDCCH and R-PDSCH in a manner of dynamicallymultiplexing the R-PDCCH and the R-PDSCH together by TDM/FDM inaccordance with R-PDCCH transmission information for a relay node ormultiplexing the R-PDCCH and the R-PDSCH together by FDM. In particular,when the eNode B transmits R-PDCCH for a random relay node, the eNode Btransmits R-PDCCH in a 1^(st) slot of a specific PRB pair (i.e., 1^(st)slot and 2^(nd) slot of a specific backhaul subframe) only and R-PDSCHin the 2^(nd) slot or may not transmit any information in the 2^(nd)slot left in idle state.

Alternatively, the eNode B may transmit R-PDCCH in both of the 1^(st)slot and the 2^(nd) slot. Alternatively, the eNode B transmit R-PDCCH inthe 2^(nd) slot only and R-PDSCH in the 1^(st) slot or the eNode B ormay not transmit any information in the 1^(st) slot left in idle state.In doing so, a detailed method for an eNode B to transmit R-PDCCH isdescribed as follows.

In the following description, first of all, a relay node, which uses DMRS (demodulation reference signal) as a reference symbol, is explained.

In case that a DL grant for a specific relay node exists in R-PDCCHonly, an eNode B transmits the R-PDCCH (containing the DL grant) for thecorresponding relay node in a 1^(st) slot of one random PRB or aplurality of physical resource blocks (PRBs) and may be able to transmitR-PDSCH for the corresponding relay node in a 2^(nd) slot of the PRB(s)having carried the R-PDCCH for the corresponding relay mode.

On the other hand, in case that both DL grant and UL grant for aspecific relay node exist in R-PDCCH, an eNode B may be able to transmitR-PDCCH for a DL grant transmission of the corresponding relay node in a1^(st) slot of one random PRB or a plurality of PRBs only. The eNode Btransmits R-PDCCH for a UL grant transmission of the corresponding relaynode in a remaining 2^(nd) slot of the PRB(s) having carried the R-PDCCHcorresponding to the DL grant or in a 1^(st) slot of other PRB(s). Inthis case, the eNode B transmits R-PDSCH for the corresponding relaynode in a remaining 2^(nd) slot of the PRB(s) having carried the DLgrant or the UL grant or may irrespectively transmit the R-PDSCH for thecorresponding relay node using other PRB(s).

In case that a UL grant for a specific relay node is carried on R-PDCCHonly, an eNode B may be able to transmit R-PDCCH for the correspondingrelay node by a PRB pair unit. In particular, the eNode B may be able totransmit a UL grant for the corresponding relay node in both a 1^(st)slot and a 2^(nd) slot of one random PRB or a plurality of PRB(s).Preferably, the eNode B may transmit the UL grant for the relay node inthe 2^(nd) slot of the one random RPB or a plurality of the PRB(s) only.

In the following description, explained is a case that a relay node usesa CRS (common reference signal) as a reference symbol.

First of all, in case that a DL grant for a random relay node exists inR-PDCCH, an eNode B may be able to transmit R-PDCCH for thecorresponding relay node in a 1^(st) slot of one random PRB or aplurality of PRB(s) only. In dong so, in a remaining 2^(nd) slot of thePRB(s) having carried the corresponding R-PDCCH, R-PDSCH for thecorresponding relay node or R-PDCCH for another relay node may betransmitted.

In case that both a DL grant and a UL grant for a random relay node exitin R-PDCCH, an eNode B may transmit the R-PDCCH for a RL granttransmission of the corresponding relay node in a 1^(st) slot of onerandom PRB or a plurality of PRBs only. In dong so, the eNode B may beable to transmit the R-PDCCH for a UL grant transmission in a 2^(nd)slot of the PRBs remaining after the DL grant transmission. On the otherhand, the eNode B may transmit the UL grant in a 2^(nd) slot of PRBsremaining after transmission of R-PDCCH for another relay node.Alternatively, the eNode B may be able to transmit the UL grant in a1^(st) slot of PRBs other than the DL grant carried PRBs.

In case that a UL grant for a random relay node exists in R-PDCCH, aneNode B may have to transmit the R-PDCCH for a UL grant transmission ofthe corresponding relay node in a 2^(nd) slot of random PRB(s). In doingso, the eNode B uses a 1^(st) slot of the corresponding PRB(s) for theUL grant transmission of the corresponding relay node or a UL granttransmission of another relay node. Alternatively, the eNode B uses the1^(st) slot of the corresponding PRB(s) for an R-PDSCH transmission ofanother relay node or may not transmit any information by leaving the1^(st) slot in idle state.

An eNode B may inform each relay node of information on an FDM regionfor an R-PDCCH transmission together with relay node assignmentinformation by RN-specific or cell-specific higher layer signaling. Indoing so, the eNode B informs each relay node of a size of a frequencyaxis of the FDM region, i.e., the number of paired PRBs. In case shownin FIG. 6 or FIG. 7, the size of the corresponding FDM region becomes 2.Moreover, in case that the eNode B is able to set a slot hopping modeshown in FIG. 6 and an interleaving mode shown in FIG. 7 together, itmay be able to inform each relay node of the setup information.

Scheme of R-PDCCH Transmission Via FDM Region and TDM/FDM Region

An eNode B may transmit an RN-specific DL grant via TDM/FDM region onlyand may also transmit an RN-specific UL grant and TPC command and acell-specific (i.e., RN-common) DL grant (e.g., a DL grant for systeminformation transmission, a DL grant for broadcast informationtransmission to all relay nodes or a relay node group) via FDM regiononly. The DL grant may be transmitted by being localized or distributedin the TDM/FDM region. The eNode B transmits R-PDSCH for thecorresponding relay node on REs remaining in the RN-specific DL grantcarried PRB(s) only. In doing so, the eNode B transmits the RN-specificDL grant using the same transmission mode (e.g., a precoding mode, atransmit diversity mode, etc.) of the corresponding R-PDSCH, which maybe semi-statically settable for each relay node by higher layersignaling.

The R-PDCCH transmitted via the FDM region is transmitted by matchingthe transmission mode setup of the corresponding FDM region, which maybe semi-statically settable together with the setup of the FDM region aswell. For instance, when an eNode B simultaneously transmits a DL grantand a UL grant for one relay node via one backhaul subframe, the DLgrant may be transmitted in the precoded transmission mode via theTDM/FDM region, while the UL grant is transmitted in the transmitdiversity mode via the FDM region.

In case that a DL grant exists in R-PDCCH for a specific relay node, aneNode B transmits all R-PDCCHs (e.g., UL grant, TPC command, etc.) forthe corresponding relay node via the TDM/FDM region. Only if a DL grantdoes not exist (e.g., a case that a UL grant or a TPC command existsonly), the eNode B may be able to transmit R-PDCCH via the FDM region.The difference from the former case lies in that an RN-specific UL grantand TPC command may be transmitted via the TDM/FDM region in case of apresence of a DL grant for the corresponding relay node.

Alternatively, an eNode B may transmit all RN-specific R-PDCCHs viaTDM/FDM region and may also transmit cell-specific (i.e., RN-common)R-PDCCH via FDM region.

The above-mentioned embodiments correspond to combinations of elementsand features of the present invention in prescribed forms. And, it isable to consider that the respective elements or features are selectiveunless they are explicitly mentioned. Each of the elements or featurescan be implemented in a form failing to be combined with other elementsor features. Moreover, it is able to implement an embodiment of thepresent invention by combining elements and/or features together inpart. A sequence of operations explained for each embodiment of thepresent invention can be modified. Some configurations or features ofone embodiment can be included in another embodiment or can besubstituted for corresponding configurations or features of anotherembodiment. And, it is apparently understandable that an embodiment isconfigured by combining claims failing to have relation of explicitcitation in the appended claims together or can be included as newclaims by amendment after filing an application.

While the present invention has been described and illustrated hereinwith reference to the preferred embodiments thereof, it will be apparentto those skilled in the art that various modifications and variationscan be made therein without departing from the spirit and scope of theinvention. Thus, it is intended that the present invention covers themodifications and variations of this invention that come within thescope of the appended claims and their equivalents.

INDUSTRIAL APPLICABILITY

Accordingly, a relay node device for receiving control information froman eNode B and method thereof are industrially applicable to such acommunication system as 3GPP LTE, 3GPP LTE-A, IEEE 802 and the like.

What is claimed is:
 1. A method of receiving signals by a communicationapparatus in a wireless communication system, the method comprising:receiving a first control channel including downlink assignment in afirst slot of a first physical resource block (PRB) pair, the first PRBpair is configured for an eNode B-to-the communication apparatustransmission; and receiving a data channel associated with the firstcontrol channel in a second slot of the first PRB pair.
 2. The method ofclaim 1, further comprising: receiving the data channel in a first slotof a second PRB pair, the second PRB pair is configured for the eNodeB-to-the communication apparatus transmission.
 3. The method of claim 1,further comprising: receiving a second control channel including anuplink assignment in a second slot of a second PRB pair, the second PRBpair is configured for the eNode B-to-the communication apparatustransmission.
 4. The method of claim 1, further comprising: receivinginformation indicating a starting orthogonal frequency divisionmultiplexing (OFDM) symbol of the first control channel, the startingOFDM symbol of the first control channel is a starting OFDM symbolwithin the first slot.
 5. The method of claim 4, wherein the informationrelated to the starting OFDM symbol of the first control channel isreceived by higher layer signaling.
 6. The method of claim 4, whereinthe starting OFDM symbol of the first control channel is an OFDM symbolof index 3 in the first slot.
 7. The method of claim 4, wherein thestarting OFDM symbol of the first control channel is communicationapparatus-specifically configured.
 8. The method of claim 1, wherein thecommunication apparatus comprises a relay node.
 9. A method oftransmitting signals by an eNode B in a wireless communication system,the method comprising: transmitting a first control channel including adownlink assignment in a first slot of a first physical resource block(PRB) pair, the first PRB pair is configured for an eNode B-to-acommunication apparatus transmission; and transmitting a data channelassociated with the first control channel in a second slot of the firstPRB pair.
 10. The method of claim 9, further comprising: transmittingthe data channel in a first slot of a second PRB pair, the second PRBpair is configured for the eNode B-to-the communication apparatustransmission.
 11. The method of claim 9, further comprising:transmitting a second control channel including an uplink assignment ina second slot of a second PRB pair, the second PRB pair is configuredfor the eNode B-to-the communication apparatus transmission.
 12. Themethod of claim 9, further comprising: transmitting informationindicating a starting orthogonal frequency division multiplexing (OFDM)symbol of the first control channel, the starting OFDM symbol of thefirst control channel is a starting OFDM symbol within the first slot.13. The method of claim 12, wherein the information related to thestarting OFDM symbol of the first control channel is transmitted byhigher layer signaling.
 14. The method of claim 12, wherein the startingOFDM symbol of the first control channel is an OFDM symbol of index 3 inthe first slot.
 15. The method of claim 12, wherein the starting OFDMsymbol of the first control channel is communicationapparatus-specifically configured.
 16. The method of claim 9, whereinthe communication apparatus comprises a relay node.
 17. A communicationapparatus for receiving signals in a wireless communication system, thecommunication apparatus comprising: a receiver, a processor, connectedto the receiver, wherein the controller controls the receiver to:receive a first control channel including a downlink assignment in afirst slot of a first physical resource block (PRB) pair, the first PRBpair is configured for an eNode B-to-the communication apparatustransmission; and receive a data channel associated with the firstcontrol channel in a second slot of the first PRB pair.
 18. Thecommunication apparatus of claim 17, wherein the processor furthercontrols the receiver to receive the data channel in a first slot of asecond PRB pair, the second PRB pair is configured for the eNodeB-to-the communication apparatus transmission.
 19. An eNode B fortransmitting signals in a wireless communication system, comprising: atransmitter; and a processor, connected to the transmitter, wherein theprocessor controls the transmitter to: transmit a first control channelincluding downlink assignment in a first slot of a first physicalresource block (PRB) pair, the first PRB pair is configured for an eNodeB-to-a communication apparatus transmission; and transmit a data channelassociated with the first control channel in a second slot of the firstPRB pair.
 20. The eNode B of claim 19, wherein the processor is furtherconfigured to control the transmitter to transmit the data channel in afirst slot of a second PRB pair, the second PRB pair is configured forthe eNode B-to-the communication apparatus transmission.